The present invention relates to a method for providing control of microorganisms at a locus by contacting said locus with a removable coating composition comprising at least one antimicrobial agent.
Microbial infection represents a serious continuing problem in human and animal health. Exposure to microbial pathogens can occur in a variety of settings, such as public facilities, hospitals, consumer products contamination, food processing plants, to name a few. Inefficient cleaning of surfaces could lead to cross contamination. Furthermore, when microbes attach to the surface, biofilm forms on the surface. Microbes within a biofilm are more resistant to disinfectants. It is thus desirable to develop an coating composition that could be applied to a variety of surfaces, and that will control the microbial contamination for a prolonged period of time. It is further desirable to have a removable coating composition that would allow for the ready removal of the said coating. The removal of the coating may be required for product quality, or in preparation for a subsequent operation such as painting, or reapplication of the antimicrobial coating composition.
The control of pathogenic microorganisms such as mold, mildew, algae, fungi and other microbes, has long been a matter of concern. Biocides such as mildewcide, antimicrobial, antiseptic, disinfectant, sanitizer, germicide, algaecide or preservatives are commonly used to remove microbes from an area and prevent their recurrence. The use of biocides in the control or prevention of microbial growth requires effective contact between the biocide and the microbe. Another requirement is for the biocide to be in contact with the microbe for the required contact time sufficient to achieve the desired level of control. Commonly encountered problems in achieving effective and long lasting control of microbial growth with current and/or commercially available biocidal compositions are: insufficient contact time caused by dripping off of the biocide solution, inefficient surface coverage by non-homogeneous coating of the surfaces, and lack of residual activity to protect the surface against fresh contamination.
Good spreading properties of the liquid antimicrobial formulation onto the surface after application is beneficial in achieving a homogeneous and continuous film, especially when spraying or aerosolizing is used as the application method. Good spreading properties can enhance the antimicrobial properties of an antimicrobial formulation by achieving complete surface coverage without leaving uncovered gaps in the created antimicrobial film in which microorganisms would still be able to grow. Antimicrobial properties can further be enhanced by reducing surface tension which allows liquid antimicrobial formulations to flow into imperfections that might exist on the surface and which may harbor microorganisms.
U.S. Pat. No. 5,585,407 provides water-based coating compositions that can be applied to a substrate to inhibit growth of microbes for extended periods of time. The coating comprises an acrylate emulsion polymer and an organoalkoxysilane and can be removed under alkaline conditions.
U.S. Pat. No. 5,017,369 provides a prophylactic treatment of mastitis in a cow between milkings comprising coating the cow teats with an aqueous composition comprising an antimicrobial agent. The composition comprises at least 2 wt % partially hydrolyzed polyvinyl alcohol, from about 0 wt % to about 10 wt % of an opacifier, about 0.1 wt % to about 10 wt % of an antimicrobial agent, and at least 65 wt % water. A water wash is used to remove the film from the cow teat prior to milking.
Thus, a need exists for a disinfectant composition capable of forming a film or coating on surfaces, including hard-to-reach surfaces, and other surfaces, such as hard surfaces formed of ceramics, glass, formica, plastics, metals and the like, which film can entrain germicidal substances such as a quaternary ammonium compound or a phenolic compound. A further need exists for a disinfectant film or coating providing extended protection against microbial contamination. Additionally a need exists for easily removable long-lasting, homogeneous and continuous films or coatings that can be applied on a variety of surfaces. None of the above methods and coatings applied in said methods provide for a durable and yet readily removable coating composition for coating surfaces described herein. Thus, the problem to be solved is the lack of a method for controlling microorganisms at a particular locus with a coating composition, comprising at least one antimicrobial agent, wherein said coating is durable, provides residual antimicrobial efficacy and is readily removable.